Hydrogen is a chemical element and its symbol is H. The atomic number of hydrogen is 1. Atomic mass of hydrogen is also 1. There are one electron and one proton present in an atom of hydrogen. There is no neutron present in hydrogen atom. The number of valence electrons present in hydrogen atom is 1. Hydrogen atom loses this electron to become stable or to make bonds with other atoms. Positive ions are formed when hydrogen atom loses an electron. The mass of hydrogen ion is equal to the mass of proton therefore, it is also known as proton.